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UNIVERSITY  OF  ILLINOIS, 

Agricultural  Experiment  Station. 

CHAMPAIGN,  AUGUST,  1890. 


BULLETIN  NO.  10. 


INVESTIGATIONS  OF  "MILK  TESTS." 

Experiment  No.  106. 

The  object  of  the  investigation  here  reported  was: 

First,  To  show  that  dairy  cows  vary  in  value  to  their  owners.  Some 
are  like  weeds  in  a  corn  field,  and  are  kept  at  an  actual  loss;  while  others 
pay  for  their  keeping  and  a  profit  besides. 

Second,  To  show  that  the  pounds  of  milk  brought  to  a  creamery  by 
its  patrons  is  not  the  most  accurate  basis  upon  which  to  pay  for  the  milk, 
since  the  butter  fat,  which  alone  is  of  value  to  the  creamery,  is  not  always 
proportionate  to  the  quantity  of  milk. 

Third,  A  trial  of  some  of  the  methods  proposed  for  analyzing  or 
testing  milk,  that  can  be  easily  and  quickly  mastered  by  those  who  wish 
to  use  them;  and  observations  on  the  accuracy  of  results  obtained  by 
these  methods. 

No  dairyman,  farmer,  nor  any  one  that  keeps  a  cow  for  her  milk, 
needs  to  be  convinced  that  one  of  the  best,  if  not  the  best  basis  to  be 
used  in  calculating  the  profit  and  loss  per  cow,  is  the  per  cent,  of  fat  in 
her  milk,  or  the  pounds  of  butter  fat  in  100  pounds  of  milk.  Other  things 
being  equal,  the  most  profitable  cow  is  the  one  that  converts  a  given 
amount  of  feed  into  the  most  butter  fat;  and  when  the  owner  of  a  herd 
of  milch  cows  is  provided  with  a  trustworthy  "  milk  tester  "  or  method 
by  which  he  can  determine  the  per  cent,  of  fat  in  each  cows  milk,  then  he 
is  able  to  weed  out  the  unprofitable  cows  in  his  herd  and  get  larger  returns 
with  much  less  labor. 

In  the  first  division  of  this  investigation  the  per  cent,  of  fat  was 
determined  in  the  milk  of  each  cow  on  three  different  farms,  where,  at 
that  season,  the  cows  had  pasture  feed  only. 


330 


BULLETIN    NO.    IO. 


[August, 


The  cost  of  keeping  a  cow  is  an  item  not  at  all  considered  here,  as 
each  individual  owner  is  the  one  best  supplied  with  facts  and  figures  from 
which  to  make  that  calculation  for  his  own  locality. 

The  following  table  gives  a  record  of  the  cows  tested.  It  shows  a 
striking  variation,  and  how  owners  of  cows  could  calculate  the  profit  and 
loss  per  cow,  if,  in  addition  to  the  per  cent,  of  fat,  they  knew  the  pounds 
of  milk  produced  by  each  cow  during  the  year. 

Although  somewhat  limited,  this  is  given  as  a  beginning  of  work  to 
be  more  extensively  followed  up,  in  the  hope  that  such  an  illustration 
may  suggest  to  those  interested  a  way  of  becoming  so  acquainted  with 
their  cows  and  business  that  the  cause  of  success  or -failure  can  be  better 
understood  each  year. 

RECORD  OF  TESTS  MADE  OF  MILK  TAKEN  AT  ONE  MILKING  FROM  38  Cows  ON 

THREE  FARMS. 


X 

c 

Breed. 

Age, 
years. 

Date  of 
last  calf. 

Days  since 
last  calf. 

Pounds 
of  milk. 

Per  cent 
of  fat. 

Pounds 
of  fat. 

I 

2 

3 

4 
5 

6 

7 
8 

9 

10 

1  1 

12 
13 

14 
15 

16 

i7 

Farm  A  —  Evening  of  J 
Holstein,  half            .... 

une  77,  / 

4 

6 

7 

10 

ii 

12 
12 
8 

9 
9 

12 

6 
3 

10 

4 

890. 
Jan.,  '90. 
Oct.,  '89. 
Oct.,  '89. 
Jan.,  '90. 
Sept.,  '89 
Nov.,  '89. 
Sept.,  '89 
Oct.,  '89. 
Oct.,  '89. 
Oct.,  '89. 
Aug.,  '89. 
Sept.,  '89 
Nov.,  '89. 
Oct.,  '89. 
Sept.,  '89 
Sept.,  '89 
June,  '89. 

ISO 
240 
240 
ISO 
270 
226 
285 
240 
240 
240 
300 
270 
211 
240 

7-5 
14-5 
7 
4-5 
7-5 
6-5 
3 
4-5 
15-5 

12 

4-5 
9-5 
5-5 

t5 

"4 

4-3 
3-7 
3-8 
4.8 

3-4 
4.2 

5-i 

2-3 

3-5 
4.0 
4.6 

2.4 

4-2 
2-3 

5-o 
2-5 
6.0 

0.32 

0-54 
0.27 

O.22 

o  25 
0.27 

0.15 

0.10 

0.54 
0.48 

O.2I 
0.23 
0.23 
O.24 
0.40 
0.36 
°-5I 

Devon,  half  

Shorthorn    

Shorthorn,  grade  

Holstein,  three-fourths  . 
Shorthorn,  half,  
Shorthorn,  grade  

Native   

Devon,  three-fourths  .  .  . 
Shorthorn,  grade  

Shorthorn,  grade      .... 

Native  

Native  

Holstein,  grade  

Jersey,  registered  

Native  

270 

Jersey,  registered  

1  8 

19 

20 
21 

22 

23 

24 

2; 
21 

^7 
28 
29 
30 
3' 
32 
33 
34 
35 
36 
37 
3j 

Farm  B  —  Morning  of  J 
Jersey,  seven-eights.  .  .  . 
Jersey,  fifteen-sixteenths 
fersey  

une  18,  i 

7 
4 

2 
2 
6 

890. 
May,  '89. 
May,  '89. 
Dec.,  '89. 
Feb.,  '90. 
Oct.,  '89. 

395 
395 
180 
130 
240 

9 
14 
6 

8-5 
'9 

5-5 
4.0 

5-6 

4-9 
4.0 

0.49 
0.56 

0-34 
0.42 
0.76 

Jersey  .  . 

Jersey,  fifteen-  sixteenths 

Farm  C  —  Evening  of  J 
Holstein,  grade  

une  18,  i 

2 

4 
3 

2 

15 
2 
2 

20  mos. 

2 
2 

20  mos. 
2 
20  mos. 
Yearling 
Yearling 
Yearling 

890. 
April,   89 
Sept.,  89 

Nov.,    89 
Dec.,    89 
Sept.,  89 
May,  '90. 
May,  '90. 
April,  '90 
June,  '90. 
June,  '90. 
May,  '90. 
April,  '90 
May,  '90 

426 
270 

225 
1  80 
270 
45 
45 
So 
H 
14 
45 
60 

45 

3 

10 

9 

i.1 

14 

T5 

6.5 

15 

9-5 
6-5 
9 

7 
7 
7-5 
6-5 

4-5 
4.2 

3-4 
3-8 
5-o 

2-3 

3-5 
3-4 
3-2 
3-6 

3'2 

2.6 

3-5. 

3-o 
3-4 
5-o 

o.  14 
0.42 

0.31 

O.2I 
0.32 
0.32 
0.40 
O.22 
0.48 

o-34 
0.25 
0.23 
0.24 

O.2I 
0.25 
0.32 

Holstein,  grade  

[three-eights 
Holstein,  half;    Jersey, 
Holstein,  grade  

Jersey,  half       

Holstein,  grade  

Holstein,  grade  

Holstein,  grade  

Holstein,  grade 

Polled  Angus  

Holstein,  grade    

Holstein,  grade   .... 

Holstein,  grade  

Holstein,  grade  

Holstein,  grade  

Holstein,  grade  

1890.]  INVESTIGATIONS    OF    MILK    TESTS.  331 

This  table  represents  a  record  of  one  milking  of  38  cows.  It  includes 
cows  from  twenty  months  to  fifteen  years  old,  that  had  been  milked  from 
14  to  426  days  since  calving.  Such  a  record  as  this  increases  in  value 
with  the  number  of  days,  weeks,  and  months  it  is  kept  up;  and,  as  ana- 
lyzing or  testing  milk  for  the  amount  of  fat  in  it  is  now  within  the  reach 
of  any  man,  no  one  need  be  satisfied  with  keeping  anything  but  profitable 
cows.  The  figures  in  this  table  showing  the  number  of  days  milked,  are 
not  exact;  but  for  purpose  of  this  investigation  they  are  near  enough  to 
the  truth. 

It  should  be  kept  in  mind  that  the  "  pounds  of  fat  produced  "  is  for 
only  one  milking. 

In  comparing  cows  for  their  butter  value,  obviously,  those  should  be 
selected  that  calved  at  about  the  same  time,  so  that  the  conditions  may 
be  the  same. 

If  we  compare  Nos.  2,  3,  22,  and  8,  we  find  that  No.  2  produced 
twice  as  much  butter  fat  as  No.  3,  and  nearly  five  and  one-half  times  as 
much  butter  fat  as  No.  8,  and  that  No.  22  produced  seven  and  one-half 
times  as  much  butter  fat  as  No.  8. 

Comparing  No.  13  with  No.  14  shows  that  nearly  twice  as  much  milk 
must  be  handled  by  the  owner  to  get  the  same  weight  of  butter  fat  from 
No.  14  as  from  No.  13.  Besides  these  extreme  cases  mentioned,  cows  can 
be  found  all  along  the  line  from  very  profitable  to  very  unprofitable. 

Taking  up  now  the  second  division  of  the  investigation: 

The  relation  of  the  quantity  of  milk  supplied  by  each  patron  to  the 
total  amount  of  butter  fat  produced  by  the  creamery  could  be  quite  defi- 
nitely determined,  if,  together  with  the  pounds  of  milk  furnished,  it  were 
known  in  each  case  what  per  cent,  of  fat  the  milk  contained.  To  illus- 
trate this,  the  milk  brought  during  one  day  by  each  patron  to  two  cream- 
eries was  analyzed,  113  tests  being  made. 

The  following  table  contains  the  record. 

The  table  shows  that  at  creamery  A  the  milk  brought  by  one-fifth  ot 
the  patrons  contained  3.6  per  cent,  fat,  or  27.7  Ib.  milk  to  i  Ib.  of  butter 
fat.  The  amount  they  brought  was  nearly  one-seventh  (14.7  per  cent.) 
of  the  total  receipts  of  milk,  and  the  butter  fat  it  contained  was  about 
one-seventh  (14.4  per  cent.)  the  total  amount  received.  In  this  case, 
then,  it  did  not  make  much  difference  with  one-fifth  of  the  patrons 
whether  they  were  paid  per  hundred  Ib.  of  milk  or  per  Ib.  of  butter  fat 
delivered,  as  each  is  nearly  the  same  proportion  of  the  total  quantity  for 
the  day.  With  the  other  four- fifths  of  the  patrons,  however,  the  propor- 
tion is  quite  irregular.  The  milk  brought  by  24  patrons,  or  nearly  one-half 
of  all,  was  49.7  per  cent,  of  the  total  quantity,  but  it  contained  from  3.7 
to  4.0  per  cent,  of  fat  and  supplied  51.9  per  cent,  of  the  total  butter  fat. 
One-fourth  of  the  patrons  delivered  26.5  per  cent,  of  the  total  milk 
brought;  but  it  contained  from  3.2  to  3.5  per  cent,  of  fat  and  supplied 
only  24.3  per  cent,  of  the  total  butter  fat  that  day. 


332 


BULLETIN    NO,   IO. 


[August, 


RECORD  OF  TESTS  MADE  OF  MILK  BROUGHT  BY  113  PATRONS  TO  TWO  CREAMERIES 

IN  ONE  DAY. 


hj 

n> 

H 
-    <•> 

|S 

w^ 

'  £ 

5' 

Creamery  A  —  June  16,  1890. 

Creamery  K  -June  18,  1890. 

Pounds 
milk. 

Pounds 
fat. 

Pounds  of 
milk  per 
pound 
of  fat. 

No.  of 
patrons 
contrib- 
uting. 

Pounds 
milk. 

Pounds 
fat. 

Pounds  of 
milk  per 
pound 
of  fat. 

No.  of 
patrons 
contrib 
uting. 

2.3 

2-5 
2.6 

2-9 

3 
3-i 

3-2 
3-3 
3-4 
3-5 
3-6 
3-7 
3-8 
3-9 
4 
4.1 

4-2 

4-3 
4-4 
4.6 

202 
31 
36 
181 

4.64 
077 
0-93 

5-25 

43-5 
40 

38.4 
34-5 

I 

I 
I 

2 

173 
250 

546 
1,188 
848 
826 
1,886 
2,169 
2,148 
1,044 
1,020 
198 
in 
277 
15° 

5-19 

7-75 
17-47 
39.20 
28.83 
28.91 
67.89 
80.25 
81.62 
40.71 
40.80 

8.12 

4.66 
ii.  61 
6.60 

33-3 
32-2 
31.2 

30.3 
29.4 
28.5 
27.7 
27 
25-3 
25.6 

25 
24.4 
23-8 
23.2 

22.7 

i 
i 

3 
3 
4 
4 
ii 
8 

9 
4 
3 
i 
i 
i 
i 

252 
888 
I,OIO 

2,123 
628 
1.555 
853 
1,178 
448 
412 

7.81 
28.41 

33-33 
72.18 
21.98 
55-98 
3I-56 
44-76 
17.48 
16.48 

32.2 
31.2 

3°-3 
29.4 
28.5 
27.7 
27 
26.3 
25.6 
25 

I 

6 

6 

9 

4 

9 
6 
6 

2 
2 

316 

13-27 

23.8 

I 

162 

7-45 

21.7 

I 

12,834 

469.61 

27-33 

55 

10,273 

362.23 

28.36 

58 

Besides  these  already  mentioned  are  a  few  extremes.  The  milk  sup- 
plied by  two  patrons  contained  3.0  and  3.1  per  cent,  fat,  and  that  supplied 
by  four  patrons,  from  4.1  to  4.4  per  cent,  fat,  making  a  difference  of  1.4 
per  cent,  between  extremes;  or  the  richest  milk  was  47  per  cent,  richer 
than  the  poorest. 

Equally  striking  illustrations  could  be  drawn  from  the  record  of 
creamery  B.  Eighty  per  cent,  of  the  patrons  supplied  milk  ranging  from 
3.2  to  3.8  per  cent,  of  fat,  but  the  milk  brought  by  one  patron  ran  as  low 
as  2.3  per  cent,  and  that  brought  by  another  as  high  as  4.6  per  cent,  of 
fat;  that  is,  one  contained  just  twice  as  much  butter  fat  in  100  Ib.  of  milk. 
If  the  richer  milk  is  received  at  $i  per  100  Ib.,  for  the  poorer  but  50  cts. 
per  100  Ib.  should  be  paid. 

In  the  third  division  of  this  investigation  an  examination  was  made 
of  five  methods  or  systems,  proposed  during  the  last  two  years,  to  be  used 
for  analyzing  or  testing  milk  by  persons  not  chemists. 

i.  "A  new  method  for  determining  fat  in  milk,"  by  F.  G.  Short. 
(Bulletin  No.  16,  July,  iSSS,  A.  E.  S.,  Univ.  of  Wis.} 

By  this  method  the  fat  in  milk  is  saponified  by  heating  two  hours 
with  alkali,  the  insoluble  fatty  acids  separated  by  boiling  one  hour  with  a 
mixture  of  equal  parts  commercial  sulphuric  and  acetic  acids  and  meas- 
ured at  a  temperature  of  about  150°  F.,  it  being  assumed  that  the  insolu- 
ble fatty  acids  constitute  87  per  cent,  of  the  total  fat  in  milk. 


1890.]  INVESTIGATIONS    OF    MILK.    TKSTS.  333 

2.  "A  new  volumetric  method  for   the  estimation  of    fat  in  milk, 
skimmed  milk,  buttermilk,  and  cream,"  by  C.  L.  Parsons.     (Ann.  Refit, 
N.  H.  A.  E.  S.,  1888,  p.  69.) 

By  mixing  the  milk  to  be  analyzed  with  alkali,  alcholic  soap,  and  gas- 
oline, the  fat  is  dissolved  and  rises  to  the  surface  in  a  layer  of  gasoline 
after  standing  some  time.  An  aliquot  part  of  the  gasoline  layer  is  heated 
at  245°  F.to  250°  F.  for  one  hour  and  a  half.  This  evaporates  everything 
but  the  fat,  which  is  measured  in  apparatus  specially  devised  for  the  pur- 
pose. 

3.  "A  new  method  of  milk  analysis  for  the  use  of  dairymen,"  by  G. 
H.  Failyer  and  J.  T.  Willard.     {Ann.  Reft  Kas.  A.  E.  S.,  1888,  p.  149.) 

The  curd  of  milk  is  dissolved  by  heating  with  concentrated  commer- 
cial hydrochloric  acid,  the  fat  collected  as  a  whole  by  solution  with  gaso- 
line, then  gasoline  evaporated  and  the  separated  fat  measured  in  the  same 
tube  in  which  the  reactions  are  made. 

4.  "A  new  process  for  determining  the  per  cent,  of  fat  in  milk,  cream, 
or  skim  milk,"  by  C.  B.  Cochran.     Patented.     (Jour.  Analytical  Chemis- 
try, Vol.  II f.,  p.  381.)     Can  be  had  of  Cochran  &  Marshall,  Philadelphia. 

In  a  flask  especially  devised  for  the  purpose,  the  milk  is  heated  at 
the  temperature  of  boiling  water  with  an  equal  quantity  of  a  mixture  of 
one-half  commercial  sulphuric  acid  and  one-half  glacial  acetic  acid. 
Washed  ethyl  ether  is  then  added,  and  after  all  ether  has  been  driven  off 
by  heat,  the  fat  which  has  separated  is  forced  into  the  measuring  tube  of 
the  apparatus  by  adding  hot  water  till  the  flask  is  full. 

5.  "The  Iowa  Station  milk  test,"  by  G.  E.  Patrick.    (Bull.  8,  la.  A. 
E.  S.}     Can  be  had  of  J.  F.  McLain,  Ames,  la. 

Milk  to  be  "tested"  is  boiled  with  an  acid  mixture  composed  of  90 
per  cent,  acetic  acid,  commercial  oil  of  vitriol,  and  hydrochloric  acid,  c. 
p.  This  acid  mixture  is  saturated  with  sulphate  of  soda.  The  fat  sepa- 
rates, rises  to  the  surface  of  the  liquid,  and  is  measured  in  the  graduated 
portion  of  the  tube.  The  amount  of  milk  taken  for  the  analysis  bears 
such  a  relation  to  the  graduations  of  the  tube  in  which  the  fat  is  meas- 
ured, that  the  measure  of  the  fat  represents  the  per  cent,  of  it  in  the  milk. 

The  necessary  special  apparatus  was  obtained  for  carrying  on  each 
one  of  these  methods,  and  analyses  were  made  of  a  great  many  samples 
of  milk.  The  table  of  analyses,  p.  235,  gives  results  obtained  by  the 
methods  that  proved,  in. use  here,  most  simple,  practical,  and  accurate. 
With  the  original  description  of  each  method  a  sufficient  number  of 
results  are  given  to  show  them  to  be  reasonably  accurate. 

Assuming  that  all  these  methods  give  equally  accurate  results,  the 
last  two — Cochran's  and  Patrick's — especially  commend  themselves  by 
the  rapidity  and  ease  with  which  the  details  can  be  comprehended  and  a 
sample  of  milk  analyzed  by  almost  any  careful  person,  though  not  accus- 
tomed to  such  work.  With  each  method,  directions  for  using  it  are  given; 
but  any  one  wishing  practical  instruction  in  the  manipulation  and  use  of 
the  apparatus,  may  find  it  to  his  advantage  to  visit  the  laboratory  of  this 


334 


BULLETIN    NO.    TO. 


[August, 


Station,  where  an  opportunity  will  be  given  him  for  instruction  in  the 
process. 

The  following  table  shows  some  observations  made  on  the  methods: 

TABLE  SHOWING   MILK,   CHEMICALS,  TIME,   AND   COST   OF   CHEMICALS    REQUIRED 

FOR  EACH  ANALYSIS. 


Method  of, 

Milk  pei- 
analysis,  c.  c. 

Re  agents  or  chem- 
icals used. 

Time  for  single  anal- 
ysis, approximate. 

Estimated  cost 
for  chemicals, 
per  analysis. 

Short. 

20 

Alkali,  10  c.  c. 
(Potash  and  soda.) 
Acid,  10  c.  c. 
(Sulphuric  &  acetic.) 

Three  and  one  half 
hours. 

Parsons. 

IOO 

Alkali,  10  c.  c. 
(Soda.) 
Alcoholic  soap,  5  c.  c. 
Gasoline,  50  c.  c. 

Two  and  one  half 
hours. 

Failyer  & 
Willard. 

10 

Hydrochloric   acid, 
8c.  c. 
Gasoline,  1  5  to  20  c.  c. 

One-half  hour. 
"  Four  analyses  in 
one   and   one-fourth 
hours." 

Cochran. 

5 

Acetic  acid,  2.5  c.  c. 
Sulphuric   acid,    2.5 
c.  c. 
Ethyl  ether,  4  c.  c. 

One-half  hour. 
"Twenty  four  anal- 
yses in  one  and  one 
fourth  hours." 

"About  one- 
half  cent." 

Patrick. 

10.4 

Acid  mixture,* 
about  15  c.  c. 

About  20  minutes. 
''  Six    analyses    in 
one-half  hour." 

fAcid   mixture, 
25  cts  per  Ib. 

*Acetic  acid  (90  per  cent),  9  volumes.      Commercial  oil  of  vitriol,  5  volumes.     Hydrochloric  acid,  c.  p., 
2  volumes.     Saturate  with  sulphjte  of  soda. 

tAssuming  each  analysis  uses  18  gr.  acid  mixture,  the  cost  per  analysis  is  about  i  cent. 

OBSERVATIONS  AND  PRECAUTIONS  NECESSARY  TO  OBTAIN  MOST  ACCURATE  RESULTS 
IN  USING  EITHER  METHOD  OF  ANALYSIS. 

Test  the  accuracy  of  the  measuring  part  of  the  apparatus  by  making 
an  analysis  of  the  same  sample  of  milk  in  each  tube  or  flask.  If  the 
same  per  cent,  of  fat  is  found  in  each  case,  the  graduation  is  probably 
correct. 

Read  the  divisions  on  the  tube  that  the  fat  occupies  after  it  has  stood 
at  least  fifteen  minutes  in  water  at  a  temperature  of  140°  F.  (60°  C.) 

Keep  in  mind  the  necessity  of  allowing  time  enough  for  all  the  hot 
fat  to  accumulate  in  the  measuring  tube,  and  also, that  by  transferring  the 
flask  or  tube  from  a  boiling  heat  to  140°  F.  the  liquid  below  the  fat  will 
cool  and  occupy  less  space  so  that  the  column  of  fat  may  fall  below  the 
graduations  of  the  measuring  tube. 

Unless  the  glass  tube  or  flask  used  in  the  analysis  is  carefully  cleaned, 
globules  of  fat  will  be  seen  sticking  to  the  sides  of  the  glass.  By  using 
hot  water  and  a  bristle  swab,  the  glass  can  be  so  cleaned  that  its  smooth 
surface  will  allow  the  hot  fat  to  move  in  an  unbroken  mass. 

In  Cochran's  method,  the  liquid  often  foams  badly  when  hot  water  is 
added  to  raise  the  fat  into  the  measuring  tube.  This  may  be  caused  by 


1890.] 


INVESTIGATIONS    OF    MILK    TESTS. 


335 


carbonic  acid  in  the  water  and  can  be  prevented  by  adding  a  few  drops 
of  some  acid  (sulphuric,  nitric,  etc.)  to  the  water  before  heating  it  for 
this  purpose. 

Outside  of  the  correct  graduation  of  the  measuring  parts  of  the 
apparatus,  the  accuracy  of  the  results  obtained  by  using  such  methods  as 
these,  depends,  to  a  controlling  degree,  on  constant  attention  to  such 
small  details  as  measuring  the  fat  in  clean  glass,  and  carefully  and  uni- 
formly reading  and  recording  the  length  of  the  fat  column. 

Estimating  the  per  cent,  of  fat  in  buttermilk  by  these  two  methods  is 
not  always  accurate,  as  will  be  seen  by  the  analyses  given  in  the  table. 
With  Cochran's  method  a  separation  of  the  fat  from  buttermilk  is  nearly 
always  obtained.  The  separation  by  Patrick's  process  is  greatly  helped 
by  boiling  the  milk  and  acid  somewhat  longer  than  usual,  adding  about 
5  c.  c.  of  ether  when  the  mixture  is  cool,  and  then  bringing  it  to  a  boil 
by  heating  gradually  till  the  ether  is  all  evaporated. 

The  following  table  shows  results  of  analyses  made  by  these  methods. 
When  more  than  one  analysis  was  made  of  a  sample  of  milk  by  the 
same  method,  sometimes  an  average  of  the  two  or  more  analyses  is  given: 


TER  CENTS.    OF  FAT   FOUND   IN  WHOLE   MILK,    SKIM   MILK,    AND   BUTTERMILK 
WHEN  ANALYZED  BY  METHODS  NAMED. 


Milk  of, 

Extraction  with  ether. 

Patrick. 

Cochran. 

Short. 

On  sand. 

On  paper. 

Herd    

Whole  milk. 

307 
3  " 

3.12 

3-05 
3.08 
3.00 

Average         

3-09 

3.06 

One  cow      

4-59 
4.46 

4-50 
480 

4.67 
4-50 

Average  

4-52 

4-65 

4.58 

One  cow  

3-7o 
3-77 
4-33 
4.78 
413 

3.60 

3.78 
4.28 
4.80 
4.06 

3-70 
3-70 
4  20 

4.70 

4.10 

3.60 
3-76 
4.15 
4.67 

3-97 

One  cow  

One  cow  

One  cow  

One  cow. 

One  cow  

4.69 

4.71* 

4.58 
4-59 

4.60 

4.55 
469 

4.60 

4-5° 
4-55 
4.67 

4.78 
4.88 
4.88 
4.88 

Average  

4.70 

4-59 

4-59 

4-57 

4.85 

One  cow   

3-88* 

3-96 

4.00 
4.00 

3-97 
4-15 

3.86 
3-97 

Average  

3-88 

3-96 

4.00 

4-03 

3-91 

One  cow  .  . 

A.^O 

4.AO 

4.20 

4..  2O 

4-iS 

d.K 

4.68 
d.<;8 

336 

PER  CENTS.  OF 


BULLETIN    NO.    IO. 
FAT,  ETC.,  Continued. 


Milk  of 

Extraction 

with  ether. 

Patrick. 

Cochran. 

Short 

On  sand. 

On  paper. 

Lab.  No.  234      .... 

Skim  milk. 

o-57 
o  62 

0.80 
0.80 

0.69 
o.6q 

Average  

O  ^Q 

0.8o 

0.69 

241  

0.48 

0.48 

O.6o 

0.48 

242 

0.66 
068* 

0.70 

O.6q 

2^0 

O.Q4 

0.94 

O.07 

080 

0.70 

2^2 

1.23 

1.28 

1.40 
1.30 
1.30 

1.27 
1.38 

1.  12 
1.  12 
1.  12 

1.52 

1.30 

1.27 

1.  12 

Average  

1.38 

1.32 

I  31 

1.  12 

261 

1.88 

1.90 

I.  GO 

1.88 

21$  .  . 

Buttermilk. 
037 

CM? 

o  oo 
o.oo 

0.^4 

2^0   .  . 

0.46 

0.47 

o  oo 

O.T; 

O.OO 

0.^2 

24Q   .  . 

0.81 

0.87 

O.QO 

o.oo 
0.60 

o.oo 

O  Q"* 

0.80 

2W  .  . 

Lost. 

0-39 
O.4O 

0.2 
O.2 

0-34 
O.74 

2*8   .. 

O.o6 

o-5 
o.« 

O.6o 

0.4O 

*Asbestos. 


E.  H.  FARRINGTON,  M.  S., 

Assistant  Chemist. 


All  communications  intended  for  the  Station  should  be  addressed, 
not  to  any  person,  but  to  the 

AGRICULTURAL  EXPERIMENT  STATION,  CHAMPAIGN,  ILLINOIS. 

The  bulletins  of    the    Experiment    Station  will  be  sent  free  of  all 
charges  to  persons  engaged  in  farming  who  may  request  that  they  be  sent. 

SELIM  H.  PEABODY, 

President  Board  of  Direction. 


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